Almost total ignorance

[amplexus]

Have you looked at the icl716 takes a voltage input and drives a seven segment lcd. a quick easy design way simpler than a pic. http://www.kitsrus.com/pdf/7106.pdf
Amplexus Ender

[DALEK]

Thanks for the link to the ICL7106 but this chip takes much to much power. I need my circuit to last two years on two AA batteries. There is no sun where these devices are going so I dont want to use photovoltaic cells. Although you could make the argument that if there is enough light to see the display, there is enough light to power the circuit.
I think the Pic is the solution but I ain't no Pic expert.

[amplexus]

Pics are easy even with no experience, but I would still consider a photovoltaic you should ber able to keep 2 aa rechargables recharged with just ambient light or at the very least extend the charge.significantly. obviously use sleep mode and clock it as slow as you can.
alltronics has some 3 1/2 digit lcd panal meters for $7.00 in singles add a op amp to scale the voltage from the rtd bridge run a 10% on time to save power c mos 555 timer astable and a swirching transistor for power and you are set. I like k.i.s.s. designs.
a
Amplexus